Synonyms of effective in English:

effective


See US English definition of effective

See UK English definition of effective

See Spanish definition of eficaz

adjective

1‘there is no effective treatment for this condition’

SYNONYMS
successful, effectual, efficacious, productive, constructive, fruitful, functional, potent, powerful
worthwhile, helpful, of help, of assistance, beneficial, advantageous, valuable, useful, of use
ANTONYMS

ineffective, incompetent, weak

2‘a more effective argument can be constructed in support of the opposite point of view’

SYNONYMS
convincing, compelling, strong, forceful, forcible, powerful, potent, weighty, plausible, efficacious, sound, valid, well founded, telling
impressive, persuasive, irresistible, credible, influential, conclusive, unanswerable, authoritative
logical, reasoned, reasonable, well reasoned, rational, lucid, coherent, cogent, eloquent, clear, articulate
ANTONYMS

weak

3‘the new law will become effective three months from now’

SYNONYMS
operative, in force, in effect, in operation, valid, official, signed and sealed
lawful, legal, licit, legitimate, legally binding, binding
Law effectual
ANTONYMS

invalid

4‘the region did not come under effective Dutch control until 1904’

SYNONYMS
virtual, practical, essential, operative, actual, implied, implicit, unacknowledged, tacit
ANTONYMS

theoretical


Phrases

    be effective

    ‘no one doubts that these measures will be effective’


    SYNONYMS
    succeed, be successful, work, work out, turn out well, go as planned, have the desired result, get results, be efficacious
    have an effect, take effect, be efficacious, function, act, have results, take hold
    informal come off, pay off, do the trick, do the business
    North American informal turn the trick
    ANTONYMS

    fail, have no effect